I'll just post it now:
This is an incomplete list, but some useful moderate/hard road or track sessions for the 800m include the following:
For aerobic endurance
* Continuous running of 20-35 minutes at a pleasantly challenging aerobic pace with the final 2-3 minutes picked up into the "hard" effort zone (the "threshold" work is usually preceded by 15-20 minutes of slower running to warm up to the quicker pace)
* 3 x 8 minutes (or 2 x 12 minutes) at a stronger, more focused aerobic pace (slightly above the threshold, with very strong - but not labored - breathing, and no tying up) with 2-3 minutes easy jogging between reps (sometimes followed by a short volume of faster work such as 4-6 x 10-30 seconds fast strides)
For oxygen uptake
* 15-20 x 200m at 3-5 seconds slower than 800m race pace with 100m jog in the same time between reps (Ex: 1:50 man runs about 30-32 seconds per 200m and jogs about 30-32 seconds per 100m)
* 12-16 x 400m at 10-12 seconds slower than 800m race pace with 45 seconds rest periods (Ex: 1:50 man runs about 65-67 per 400m)
Event-specific anaerobic work
* 1 x 600m at 800m race pace, do not stop but go immediately into 600m jog in 4:30, 2 x 300m at the same pace or faster with 300m jogs (no stopping) in 2:15 after each rep, 2-4 x 150m at the same pace or faster with 150m jogs (no stopping) in 60-70 seconds between reps (Ex: 1:50 man runs 1:22 for 600m, 39-41 for 300m reps and 19-20 for 150m reps)
* 500m at 800m race pace, 2 minutes rest, 300m at same pace, 5 minutes walk/jog, 500m at same pace, 2 minutes rest, 200m all-out (Ex: 1:50 man runs 1:08, 41, 1:08, 24-25?)
* 3 x 200m at 800m race pace with 2 minutes rest between reps, 5 minutes walk/jog after last rep, 2-3 sets of (300m at 800m race pace, 1 minute rest, 200m at 400m race pace) with 5 minutes walk/jog between sets (Ex: 1:50 man runs 27 for 200m warmup reps, 41 for 300m reps and 24-ish for 200m reps)
* 4 x 400m at 800m race pace or slightly faster with 3-4 minutes rest between reps (Ex: 1:50 man runs 53-55 per 400m)
Faster speed work
* 6 x 10 seconds accelerations (each one slightly faster so the last 2 finish at top speed), 15-20 seconds recovery between reps (after decelerating to a complete stop), 2 minutes rest after last rep, 1 x 150m all- out, 5 minutes walk/jog, 4 x 10 seconds medium speed accelerations, 15-20 seconds recovery between reps
* 6 x 10 seconds accelerations (each slightly faster), walk or slow jog back to start for recovery, 2 minutes rest after last rep, 1 x 150m all-out, 2 minutes rest, 1 x 300m at 800m race pace, 2 minutes rest, 1 x 300m all-out, 5 minutes walk/jog, 4 x 10 seconds medium speed accelerations (Ex: 1:50 man runs 17-ish for 150m, 41 for first 300m and 35-37? for second 300m)
* 350m-300m-250m-200m each all-out with 400m walk between reps (Ex: 1:50 man runs 24-25 200m pace on each rep)
Precede each fast session with a warmup jog of 12-20 minutes (plus some short warmup strides if not included in the session) and follow each with a jog of 10-15 minutes. Very light static stretching is optional prior to the fast portion of a session and is often helpful following the post-workout jog.
Use the very high-intensity sessions sparingly lest they become counterproductive. High-speed work during the last 9-10 days prior to the most important competitions should consist of mostly short strides.